N, K = map(int,input().split())

G = [[] for k in range(N)]
for k in range(N-1):
    a, b, c = map(int,input().split())
    G[a-1].append([b-1,c])
    G[b-1].append([a-1,c])

visited = [-1]*N
visited[0] = 1
ha = dict()
def dfs(ima,mae,keiro):
    if len(G[ima]) == 1:
        for e in keiro:
            if e in ha:
                ha[e] += 1
            else:
                ha[e] = 1
    for tsugi in G[ima]:
        if tsugi != mae:
            if visited[tsugi[0]] == -1:
                visited[tsugi[0]] = 1
                dfs(tsugi[0],ima,keiro+[(ima,tsugi[0])])
dfs(0,-1,[])
ans = 0
nodes = []
for k in range(N):
    for e in G[k]:
        if (k,e[0]) in ha:
            ans += e[1]*ha[(k,e[0])]
            nodes.append([e[1],e[1]*ha[(k,e[0])]])

N = len(nodes)
dp = [[0]*(K+1) for k in range(N+1)]
for i in range(N):
    for w in range(K+1):
        if w >= nodes[i][0]:
            dp[i+1][w] = max(dp[i][w],dp[i][w-nodes[i][0]]+nodes[i][1])
        else:
            dp[i+1][w] = dp[i][w]
print(ans+dp[N][K])